1. Field of the Invention
The present invention relates to a cleaning method and a cleaning unit of an ink ejection section in an image forming apparatus such as an inkjet color printer, and to an image forming apparatus.
2. Description of Related Art
In image forming apparatuses, there are apparatuses of the type which forms an image on a paper by ejecting an ink onto a paper as a recording medium, such as inkjet color printers. These image forming apparatuses are provided with an image formation section capable of forming an image, a paper storage section to store a paper whose surface is used for image formation, a paper transport section to transport a paper to the image formation section, and a paper discharge section capable of discharging a paper with an image formed on the surface thereof. In these image forming apparatuses, the paper stored in the paper storage section is transported to the image formation section by the paper transport section, and the image based on image information is formed on the paper. The paper after being subjected to the image formation by the image formation section is then discharged into the paper discharge section.
Specifically, the image formation section has an ink ejection section capable of ejecting an ink onto a paper, and a cleaning unit to clean the ink ejection section as shown in, for example, Japanese Unexamined Patent Application Publication No. 2002-361879. During an image forming operation, the ink is ejected onto a paper from the ink ejection section, and the ink ejection section is cleaned by the cleaning unit. This cleaning unit is provided with a cleaning blade formed by an elastic material, and a wet porous elastic body.
In the cleaning unit as described above, after the ink of the ink ejection section is absorbed by the porous elastic body, the surface of the ink ejection section is wiped off by the cleaning blade, that is, the moisture and the like at the ink ejection section are wiped off. However, if the ink cannot be completely absorbed by the porous elastic body, cleaning efficiency becomes poor, and the water repellency of the ink ejection section is deteriorated by the adhered and dried ink at the ink ejection section. Thus, the deteriorated water repellency of the ink ejection section leads to deterioration of image quality.
Also in a state in which the resin composition contained in the ink is adhered to the ink ejection section, image quality might also be deteriorated by the difficulty in controlling the ink ejection. Particularly in an elongated line head, because the amount of ink adhesion is larger than that of a serial head, there is a large possibility that image quality may be deteriorated due to insufficient ink removal. That is, the ink adheres to the ink ejection section and then dries there, so that the resin composition is solidified around an ink ejection hole provided at the ink ejection section. When the ink is ejected in this state, for example, the solidified resin composition and the ejected ink contact with each other, and the normal ink ejection may be hindered to cause image quality deterioration.